These are hard for anyone to remember; just follow the drunken sailors and sing along…

Heaving moving up and down (linear, along y-axis):

Swaying moving left and right (linear, along x-axis):

Surging moving forward and backward (linear, fore and aft):

Pitching tilting forward and backward (rotational, along y-axis about the center point):

Yawing turning left and right (rotational, change heading side to side):

Rolling tilting side to side (rotational, about horizontal fore and aft center line):

Long days at sea is the best place to engage in disciplined practices of body movement:

But do not start with this. It reads: “This version of the posture requires considerable strength in the neck, shoulders, and back, requiring years of practice to achieve. It should not be attempted without supervision.”

These experienced practitioners show us examples of forward pitch and backward pitch.
(Apologies: sources unknown)